Grey Alder vs Mountain Alder - TreeTime.ca

Grey Alder vs Mountain Alder

Alnus incana

Alnus incana subsp. tenuifolia

NOT AVAILABLE THIS SEASON - MIGHT RETURN

CUSTOM GROW

Grey Alder
Mountain Alder

River Alder is a large shrub or small tree with a multi-stemmed, spreading habit. It is an excellent tree to plant if you want to stabilize the soil near rivers and creeks.

Unlike the other alder varieties, River Alder is attractive enough to be included in riverside plantings by municipal and provincial park organizations.

Note: We use Grey Alder for Alnus incana. This species is also known by many other common names, including River Alder, Speckled Alder, and others. Please confirm the scientific name to ensure you are ordering the correct plant.

Mountain Alder is a native cold-hardy shrub or small tree often found along streams and in moist forested habitats. Its nitrogen-fixing ability enriches soils and supports surrounding vegetation, while its extensive root system helps stabilize streambanks and slopes. The fast growth rate allows it to establish quickly on disturbed sites, making it especially valuable in reclamation, restoration, and erosion control projects.

Often forming dense thickets, Mountain Alder enhances habitat quality in riparian and upland areas. It provides food and cover for various wildlife, including birds and small mammals. Recognized as an important species for soil and water conservation, it is well suited for riparian planting, naturalization, and ecological restoration.

Note: We use Sitka Alder for Alnus incana subsp. tenuifolia. This species is also known by many other common names, including Grey Alder, River Alder, and others. Please confirm the scientific name to ensure you are ordering the correct plant.

Grey Alder Quick Facts

Mountain Alder Quick Facts

Zone: 1a
Zone: 1a
Height: 8 m (25 ft)
Height: 6 m (20 ft)
Spread: 4 m (12 ft)
Spread: 3 m (10 ft)
Light: full sun
Light: partial shade, full sun
Moisture: normal, wet
Moisture: normal, wet
Growth rate: fast
Growth rate: medium
Life span: short
Life span: medium
Growth form: multi-stemmed, thicket-forming
Spreading: rhizomes - medium, seeds - low, layering - low
Suckering: none


Fall colour: yellow to orange
Bark: smooth, gray to brown
Fruit: small catkins
Cones: small brown cones
Hybrid: no
Hybrid: no
Catkins: yes
Catkins: yes


Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, NU, PE
Native to: AB, BC, SK, YT, NT
Other Names: hoary alder, river alder, speckled alder
Other Names: river alder, speckled alder, thin-leaved alder, thinleaf alder, western river alder